Part 212 - Fuel Injection Technology... (",)

What are some advantages and disadvantages of having a Electronic Fuel Injection motorcycle?

Advantages of direct fuel injection

The first advantage is the ease of starting in any climate, as EFI monitors the environment and adjust fuel delivery to suit. The second reason to go for a EFI motorcycle would be the more efficient combustion across entire rev range, giving better fuel economy. And the engine can withstand more torque loads at low rpm as induction is not dependent on intake vacuum to maintain delivery of fuel to cylinder, meaning the engine won't bog under higher load.

Disadvantages of direct fuel injection

The primary disadvantages of direct injection engines are complexity and cost. Direct injection systems are more expensive to build because their components must be more rugged -- they handle fuel at significantly higher pressures than indirect injection systems and the injectors themselves must be able to withstand the heat and pressure of combustion inside the cylinder.

The fuel system is dependent on the function and reliability of an immersed fuel pump inside the fuel tank. The motorcycle becomes completely battery-dependent, death battery means death bike.

Engine Sensors

­In order to provide the correct amount of fuel for every operating condition, the e­ngine control unit (ECU) has to monitor a huge number of input sensors. Here are just a few:

• Mass airflow sensor - Tells the ECU the mass of air entering the engine
• Oxygen sensor(s) - Monitors the amount of oxygen in the exhaust so the ECU can determine how rich or lean the fuel mixture is and make adjustments accordingly
• Throttle position sensor - Monitors the throttle valve position (which determines how much air goes into the engine) so the ECU can respond quickly to changes, increasing or decreasing the fuel rate as necessary
• Coolant temperature sensor - Allows the ECU to determine when the engine has reached its proper operating temperature
• Voltage sensor - Monitors the system voltage in the car/motorcycle so the ECU can raise the idle speed if voltage is dropping (which would indicate a high electrical load)
• Manifold absolute pressure sensor - Monitors the pressure of the air in the intake manifold
• The amount of air being drawn into the engine is a good indication of how much power it is producing; and the more air that goes into the engine, the lower the manifold pressure, so this reading is used to gauge how much power is being produced.
• Engine speed sensor - Monitors engine speed, which is one of the factors used to calculate the pulse width